Temporal distance in surgery is defined as the time between a providers performance of a particular procedure, and there is evidence that longer temporal distance is associated with poorer patient outcomes. It is hypothesized that longer distance might also be associated with greater per patient resource use. The primary aim of this project are to examine the impact of temporal distance and provider volume on quality, as measured by patient outcomes, and efficiency in the context of the US medical care system. We are going to examine the two most common surgical procedures used to treat coronary artery disease, CABG and PCI, as well as AAA repair surgery, carotid endarterectomy and aortic valve repair. There are two secondary aims. The first is to examine how many procedures subsequent to a longer period away from the operating room the temporal distance impact remains. The second is to assess the impact of the temporal distance between the specific procedures is either mitigated or accelerated by surgeons'years of experience. We will employ the inpatient data from the Pennsylvania Health Care Cost Containment Council (PHC4) for the years 2006-2009. We will first employ basic logistic regression modeling techniques to examine the temporal distance effect while simultaneously adjusting for patient risk and provider volume. We then will employ fixed effects modeling to deal with the unobserved heterogeneity of the providers. This study is intended to probe for the existence of temporal distance effects on value, as measured by quality and efficiency. Once the magnitude of these effects are demonstrated, they can be addressed by appropriate OR management strategies and licensing policy. In addition our study will inform hospital regionalization policy which to this point has been based solely on volume effects. PUBLIC HEALTH RELEVANCE: The proposed research has important implications for public health as it addresses issues related to the quality, safety and efficiency of surgical care. Results of this research could lead to the design of interventions, both managerial and policy related, that would provide improvements in quality and the value of major surgery.